VI Client Fails to Add a Host (2257)
This can occur if a previously configured NFS mount in the service console is not available at the time you add the host.
If the service console on a host has any NFS mounts, check the availability of the mounts before adding the host to VirtualCenter. Do this on the host machine by logging in to the service console or by checking your NFS servers.
If you cannot reach a mount, unmount it with the command